Method for controlling electrochemical drilling

Abstract

In the electrochemical drilling of a hole completely through a workpiece, the present invention proposes operating the power supply in a current regulating mode. Initially, a hollow cathode is positioned adjacent to a workpiece in which one or more holes are to be drilled. An electrolyte is flowed through the cathode and against the workpiece. A constant electrical current is applied between the cathode and the workpiece across the electrolyte. Then the cathode is advanced at a constant rate toward the workpiece for the drilling of the hole(s), while maintaining the electrolyte flow and current substantially constant.

What is claimed is: 
     
       1. In the method of electrochemical drilling using an electrochemical drilling machine in which an insulating hollow cathode is positioned in closely spaced relation to an anodically charged workpiece, the insulating hollow cathode and the anodically charged workpiece having an associated power supply, and a highly conductive electrolyte is passed through said cathode to become cathodically charged and to impinge on said workpiece to initiate hole drilling, the improvement which comprises: operating the power supply in a current regulating mode;   monitoring-amperage output from-the power supply to the drilling machine;   maintaining a constant amperage output from the power supply to the drilling machine by manually monitoring amperage output from the power supply and using internal regulating means in the power supply to output a constant current to the drilling machine, wherein the internal regulating means comprises an ammeter in series with a variable resistor; and   advancing the cathode-at a constant rate toward the workpiece to initiate hole drilling while maintaining the electrolyte flow and current substantially constant.   
     
     
       2. A method as claimed in claim 1 wherein the step of maintaining a constant amperage from the power supply further comprises the step of controlling a regulator of the power supply to maintain constant amperage. 
     
     
       3. A method as claimed in claim 1 further comprising the step of providing an ammeter for measuring current output from the power supply. 
     
     
       4. A method as claimed in claim 1 wherein the step of maintaining a constant amperage from the power supply comprises the steps of: manually monitoring amperage output from the power supply; and   using external controlling means associated with the power supply to output a constant current to the drilling machine.   
     
     
       5. In the electrochemical drilling of a hole completely through a workpiece, the method comprising the steps of: positioning a hollow cathode adjacent to the workpiece;   flowing an electrolyte through the cathode and against the workpiece;   applying a constant electrical current between the cathode and the workpiece across the electrolyte by manually monitoring amperage output from the power supply and using internal regulating means in the power supply to output a constant current to the drilling machine, wherein the internal regulating means comprises an ammeter in series with a variable resistor; and   advancing the cathode at a constant rate toward the workpiece for the drilling of the hole while maintaining the electrolyte flow and current substantially constant.